TaskLocalの引き継ぎはasync letやTask {}では行われる

main.swift

import Foundation

enum MyValue {
    @TaskLocal static var foo: Int = 0
}

func myFunc(@_inheritActorContext _ op: @Sendable @escaping () async -> ()) async {
    await withCheckedContinuation { c in
        DispatchQueue.global().async {
            Task {
                await op()
                c.resume(returning: ())
            }
        }
    }
}

func myFunc2(_ op: @Sendable @escaping () async -> ()) async {
    Task {
        await op()
    }
}

let task = Task {
    print(#line, MyValue.foo)
    await MyValue.$foo.withValue(1) {
        print(#line, MyValue.foo)
        await myFunc {
            print(#line, MyValue.foo)
        }
        async let aa = myFunc2 {
            print(#line, MyValue.foo)
        }
        await myFunc2 {
            print(#line, MyValue.foo)
        }
        await aa
    }
}
task.cancel()
print("main end")

stdout

25 0
27 1
main end
29 0
35 1
32 1